Needle bar



Jan. 1, 1929.

c. H. GREENWOOD NEEDL BAR F'le AJune 9, 192s Patented Jan. 1, 1929.

nutren stares CHARLES I-I. GREENWOOD, 0F CANTON, OHIO.

NEEDLE BAR. p

Application filed June 9, 1923.

This invention relates to needle bars for sewing machines and has forits objects to provide a selil lubricating needle bar provided with asimple and easily operated needle clamp having means for quickly.directing the needle into position and clamping means for instantlytightening or loosening the needle within the clamp.

The above and other objects may be attained by constructing the needlebar in the manner illustrated in the accompanying drawing, in which-Figure 1 is a side elevation of a needle bar embodying the invention;

Fig. 2, a longitudinal sectional view through the needle bar upon alarger scale;

Fig. 3, a section on the line 3-3, Fig. 2, upon an enlarged scale; and nFig. 4, a detached perspective View oi the shim. l

Similar numerals refer to similar parts throughout the drawing.l

The needle bar 1 is preferably tubular and is slida-bly mounted forvertical reciprocation within a bearing or bushing indicated at 2. Aplug 3 is xed in the lower end of the needle bar and provided with acircular bore 4 to receive the needle 5.

The lower end of the needle bar is preferably reduced in diameter as at6 to accommodate the cylindrical shim plate 7. The clamp comprises thecollar portion 8 which surrounds the needle bar and shim and the inter.-nally threaded boss 9 which contains the clamping screw 10v having theknurled head 11.

The screw is provided with the reduced shank 12 which is located throughthe longitudinal slot 13 in the shim. A rusto-conical head 14 isprovided upon the inner end of the shank 12 and extended through theaperture 15 in the needle bar, and into the frusto-conical aperture 16in the plug 3, the flat, inner end 17 thereof being arranged to engagethe flat side 18 of the needle.

In assembling the clamp upon the lower end of the needle bar, the plug 3is first driven into place after which the needle clamp is placed aroundthe lower end of the needle bar and the screw 10 inserted intoengagement with the conical aperture 16 of the plug. The

shim 7 is then driven into place over the lower end of the needle bar,frictionally engaging the needle bar and the collar portion of theSerial No. 644,396.

clamp, the slot 13 receiving the reduced shankv 12 of the clampingscrew.

The movement of the clamping screw is thus limited, the Hat side o1 theneedle being engaged by the end of the conical head 14, limiting theinward or clamping movement of the screw, while the shim will be engagedby the conical head 14 when the screw is loosened, limiting the outwardmovementof the screw. v

A collar 19 is provided around the upper portion of the needle bar andprovided with the boss 20 which is internally threaded' to receive theset screw 21, said boss forming a journal for a link which providesreciprocatory motion to the needle bar. A threaded cap 22is provided forclosing the upper end of the needle'bar.

An aperture 23 is provided near the upper end of the needle bar andregisters with the bore 24 and the collar 19 and similar apertures 25may be provided intermediate the ends of the needle bar, a felt plug 26being located in the upper end of the needle bar and covering saidapertures.

The hollow needle bar thus forms an oil well as shown at 27, suitablelubricating oil being carried therein.l Thus as the needle bar isreciprocated, the oil will be splashed upon the felt pad 26 and allowedto pass outward through the apertures 23 and 25, lubricating the journal20 and' the bearing 2.

It will be noted that the lower end of the needle bar and clamp andblock 3 are concaved as shown at 28, in order to assist in guiding theneedle into the central bore 4. When the screw 10 is in the loosenedposition, the extremity ofl the conical head 14 thereof will stillproject into the central bore 4 of the block, as shown in Fig. 3, thuspreventing the needle from being Ventered into the bore 4 in anyexcepting the proper position.

1. A needle bar having a bore in its lower end to receive a Hat sidedneedle, a clamp comprising a collar portion surrounding the bar, aclamping screw inthe collar provided with a reduced shank and a headextended into the bore and having a Hat end for engagement with theneedle anda cylindrical plate between the bar and collar provided with anarrow slot to accommodate the reduced shank of the screw and to preventthe head from being Withdrawn entirely from the bore. 2. A needle barhaving a bore in its lower end to receive a l'at sided needle, a clampcomprising a collar portion surrounding the bar,

5 a threaded boss upon the collar, a clamping screw in the threaded bossprovided Witha reduced shank, and a head extended into the bore andhaving a Hat end for engagement with the needle, and a shim between thebar and collar provided With anarrow slot to accommodate the reducedshank of' the screw andl to prevent the head from being Withdrawnentirely from the bore.

Iny testimony that I claim the above, I have hereunto subscribed myname.

CHARLES H. GREENWOOD.

